Hearing devices are wearable hearing apparatuses serving to assist those with impaired hearing. To meet the numerous individual needs, different models of hearing devices are available, such as behind-the-ear hearing devices (BTE), hearing devices with an external earphone (RIC: receiver in the canal) and in-the-ear hearing devices (ITE), for example also concha hearing devices or canal hearing devices (ITE, CIC). The hearing devices listed by way of example are worn on the outer ear or in the auditory canal. However bone conduction hearing aids, implantable and vibrotactile hearing aids are also commercially available. With these the impaired hearing is stimulated either mechanically or electrically.
In principle the essential components of hearing devices comprise an input transducer, an amplifier and an output transducer. The input transducer is generally a sound receiver, e.g. a microphone, and/or an electromagnetic receiver, e.g. an induction coil. The output transducer is frequently in the form of an electroacoustic transducer, e.g. a miniature speaker, or an electromechanical transducer, e.g. a bone conduction earphone. The amplifier is generally integrated in a signal processing unit. This basic structure is shown in FIG. 1 based on the example of a behind-the-ear hearing device. One or more microphones 2 for receiving ambient sound are built into a hearing device housing 1 to be worn behind the ear. A signal processing unit 3, which is also integrated in the hearing device housing 1, processes the microphone signals and amplifies them. The output signal of the signal processing unit 3 is transmitted to a speaker or earphone 4, which outputs an acoustic signal. The sound is optionally transmitted to the eardrum of the device wearer by way of a sound tube, which is fixed in the auditory canal by means of an otoplastic. Energy is supplied to the hearing device and in particular to the signal processing unit 3 by a battery 5 which is also integrated in the hearing device housing 1.
The functionality of hearing devices is greatly impaired by feedback. Such feedback not only occurs with hearing devices in which the earphone and microphones are accommodated in one housing. Hearing devices with so-called external earphones (RIC) frequently also experience feedback due to a transmission of vibrations between the earphone and the housing of the main part of the device. The vibrations are then conducted to the corresponding microphone by way of the housing. It is possible for the vibrations to be transmitted in particular because of the rigidity of the cable or wire connecting the earphone to the main part of the hearing device. This problem is particularly acute with so-called cymba devices but also with other RIC devices, in which the wire holds the device in or on the auricle and therefore has to be designed to be correspondingly rigid.
Until now feedback problems were primarily resolved by signal processing measures (feedback cancelers). A mechanical solution is also known internally at least, according to which a microphone for example is adhered to the hearing device housing, so that the resonant frequency is displaced accordingly.
A flexible earpiece for a hearing aid is known from the publication US 2002/006209 A1, which can adjust to an auditory canal when worn. A spring is provided in the internal structure of the earpiece, to allow a high level of lateral and transverse yield.
An earpiece for a hearing aid, into which an earphone is inserted, is known from the publication EP 2 026 605 A1. The earphone is held by an elastic transition piece in a friction locked manner and thus supported in this in an elastic manner.